The phrase "most well set" refers to something being placed or positioned in an optimal manner. Some antonyms to this phrase could include poorly placed, awkwardly positioned, misaligned or haphazardly arranged. These terms denote the opposite of being well-set, indicating that something is not arranged or placed optimally. A few other antonyms might include imbalanced, unsteady, crooked, unstable or disorganized. These words suggest something that is less than perfect, indicating that the placement or arrangement is not optimal or effective. When looking for a word that means the opposite of "most well set," it is important to consider the context and the specific meaning intended.